Evaluation of foal production following intracytoplasmic sperm injection and blastocyst culture of oocytes from ovaries collected immediately before euthanasia or after death of mares under field conditions

In vitro fertilization of in vitro-matured equine oocytes: effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer

..Equine expanded blastocysts may be vitrified after collapsing them via micromanipulation, with normal pregnancy rates after warming and transfer. Many of these recently developed techniques are now in clinical use...

Evaluation of foal production following intracytoplasmic sperm injection and blastocyst culture of oocytes from ovaries collected immediately before euthanasia or after death of mares under field conditions

..Time of oocyte recovery and duration of maturation significantly affect the rate of blastocyst development. Oocytes with Cp and Ex cumuli have similar developmental competence to the blastocyst stage...

In vitro fertilization of in vitro-matured equine oocytes: effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer

K HinrichsSection of Large Animal Clinical Sciences, Tufts University School of Veterinary Medicine, North Grafton, MA 01536, USATheriogenology 54:1285-93. 2000

..One foal died at birth. Establishment and maintenance of pregnancy in these mares indicates that nonovulating, hormone-treated mares may offer an alternative to cyclic recipients in oocyte transfer programs...

..Condensation of chromatin in oocytes in smaller apparently viable follicles, while associated with acquisition of meiotic competence, may represent a pre-atretic change...

CatSper and the relationship of hyperactivated motility to intracellular calcium and pH kinetics in equine sperm

Shavahn C LouxDepartment of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, TexasBiol Reprod 89:123. 2013

..Procaine does not appear to act via CatSper in equine sperm, and its initial hyperactivating action is not dependent upon external calcium influx. ..

Activation of equine nuclear transfer oocytes: methods and timing of treatment in relation to nuclear remodeling

Young Ho ChoiDepartments of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A and M University, College Station, Texas 77843 4466, USABiol Reprod 70:46-53. 2004

..These results indicate that although nuclear remodeling occurs rapidly in equine cytoplasts, early activation does not improve embryonic development after reconstruction...

A viable foal obtained by equine somatic cell nuclear transfer using oocytes recovered from immature follicles of live mares

Young Ho ChoiCollege of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, Texas, USATheriogenology 79:791-6.e1. 2013

..In conclusion, this is apparently the first report of production of a viable cloned foal from oocytes collected from immature follicles of live mares, supporting the possibility of cloning using oocytes from selected mares...

..that direct nuclear injection using the Piezo drill is an efficient method for nuclear transfer in horse and cattle oocytes and that sperm extract can efficiently activate horse oocytes both parthenogenetically and after nuclear transfer..

Effect of co-culture with theca interna on nuclear maturation of horse oocytes with low meiotic competence, and subsequent fusion and activation rates after nuclear transfer

Young Ho ChoiDepartment of Veterinary Physiology, College of Veterinary Medicine, Texas A and M University, College Station 77843 4466, USATheriogenology 57:1005-11. 2002

..In vitro matured equine oocytes have the potential to develop into embryos after nuclear transfer; this is the first full report of production of cloned embryos in this species...

Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen-thawed spermatozoa

..2 medium results in a similar cleavage rate but reduced number of cells compared with in vivo culture within the oviduct. Bovine oocytes may be useful as models for assessing sperm function in horses...

..The association of follicle atresia with increased meiotic competence suggests that acquisition of meiotic competence is related to a loss of suppressive activity by the degenerating follicle...

Hyperactivation of stallion sperm is required for successful in vitro fertilization of equine oocytes

L A McPartlinDepartments of Clinical Sciences and Biological and Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USABiol Reprod 81:199-206. 2009

..Conversely, sperm incubated in capacitating conditions but not treated with procaine did not fertilize (0%). These results support the hypothesis that capacitation and hyperactivation are required for successful IVF in the equine...

Equine blastocyst development after intracytoplasmic injection of sperm subjected to two freeze-thaw cycles

..Non-motile spermatozoa from reprocessed semen may also achieve embryo development after ICSI. To our knowledge, this is the first report evaluating the ability of refrozen spermatozoa to produce embryos by ICSI in any species...

Description and genetic analysis of three sets of monozygotic twins resulting from transfers of single embryos to recipient mares

..3 sets of monozygotic twins resulting from transfers of single embryos to recipient mares were examined...

Ejaculate and type of freezing extender affect rates of fertilization of horse oocytes in vitro

L M RoasaDepartment of Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, TX 77843, USATheriogenology 68:560-6. 2007

..These factors may help to explain the great variability in fertilization rates reported with equine IVF, both among and within laboratories...

Transport of equine ovaries for assisted reproduction

B I RibeiroDepartment of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, TX 77843 4466, USAAnim Reprod Sci 108:171-9. 2008

..Further work is needed to determine if there is a critical time before 7h post-mortem by which equine oocytes should be recovered to maximize developmental competence...

In vitro development of equine nuclear transfer embryos: effects of oocyte maturation media and amino acid composition during embryo culture

Y H ChoiDepartment of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A and M University, College Station 77843 4466, USAZygote 11:77-86. 2003

..CZB-C medium may be used for culture of equine embryos with results similar to those obtained with G1.2 medium, thus providing a base medium that may be modified for further study of culture requirements of equine embryos...

Effect of holding at room temperature on initial chromatin configuration and in vitro maturation rate of equine oocytes

C C LoveDepartment of Physiology and Pharmacology, College of Veterinary Medicine, Texas A and M University, College Station 77843, USATheriogenology 57:1973-9. 2002

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Production of a mitochondrial-DNA identical cloned foal using oocytes recovered from immature follicles of selected mares

Young Ho ChoiCollege of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, Texas, USATheriogenology 82:411-7. 2014

..051). These data indicate that exercising mares in a hot and humid environment are associated with changes in ovarian follicle development and ovulation, and a reduction in embryo recovery...

Patterns of intracellular calcium oscillations in horse oocytes fertilized by intracytoplasmic sperm injection: possible explanations for the low success of this assisted reproduction technique in the horse